The present invention relates to the field of maintenance of swimming pools and the like, and provides a simple, reliable, and efficient cleaning device for such pools.
Vacuum cleaners for swimming pools have been known, as exemplified by the cleaning device shown in U.S. Pat. No. 4,581,075. The latter patent, the disclosure of which is hereby incorporated by reference herein, describes a cleaner having a pump and filter assembly which floats on the surface of a pool, while a vacuum head is moved around the pool to clean it. The flow of water produced by the pump also provides a propulsion force to drive the cleaner around the pool.
Pool cleaners such as that shown in the above-cited patent, and other similar pool cleaners of the prior art, have the disadvantage that they require filters disposed upstream of the pump. Positioning the filter ahead of the pump degrades the performance of the cleaner because the pressure exerted by the water in the pool is inherently limited, and as the filter fills with debris, it becomes increasingly difficult to push water through the system. It then becomes necessary to reduce the height of the vacuum head, relative to the bottom of the pool, so as to maintain efficiency of operation. As the filter fills even more, it becomes increasingly difficult to maintain a desired throughput. The result is that, with pool cleaners of the prior art, it is generally necessary to make two or more passes through each area of the pool, because as the filter is somewhat clogged, the cleaner may be moving only half the flow of water that it did when the filter was fresh.
The present invention provides a pool cleaner which solves the above-described problem. The pool cleaner of the present invention substantially reduces the time and effort required to clean a pool. Moreover, in one embodiment, the present invention substantially automates the task of changing filters, thereby further reducing the time and effort required to clean a pool.